I think I maybe able to put you minds at ease. I have two MBP 17" late 2011. Once purchased in November of 2011 and one purchased this past Sunday 2/25/12. The MBP purchased in November required, accepted and installed the 2.7 firmware. The one most recently did not present the download in the software update panel, did not install it when I manually downloaded the firmware update and kept presenting me with the info "This system does not support this update." (BTW I tried to install 2.7 on a stock Lion drive with no other software installed on the most recently purchased MBP, no luck)
Here is my Sunday's purchase profile: Note the boot rom is different then what the Firmware 2.7 states it should be. My theory is that there was a hardware change in the units produced mid December or early January to now that nullified the 2.7 firmware upgrade. Go to
http://www.chipmunk.nl/klantenservice/applemodel.html and enter your serial number to find out exactly when your MBP was made. I will venture to bet all those that can't install the 2.7 firmware were made after late December 2011 or early 2012 to present. I believe there is no concern if your mac is not displaying any issues. HOPE THIS HELPS...
Hardware Overview:
Model Name: MacBook Pro
Model Identifier: MacBookPro8,3
Processor Name: Intel Core i7
Processor Speed: 2.5 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 8 MB
Memory: 8 GB
Boot ROM Version: MBP81.0047.B26
SMC Version (system): 1.70f5
This is when my recent MBP was made and this is the one that I believe does not require the 2.7 firmware:
Model introduced: 2011
Production year: 2012
Production week: 7 (February)